Development of Salivary Gland Proteins

果蝇的激素反应性胶基因表达于 在三龄后期幼虫的唾液腺中含量很高。 与其他胶水基因不同，Sgs-4在早期表达， 在第二个组织中，前胃。博士 Beckendorf建议使用足迹法，体外突变， 和生殖系转化来确定哪个顺式作用于 序列控制着这种独特的表达模式。因为党卫军- 4增强子由多个部分可互换的 元素，这些元素的相互作用和差异 将审查其监管职能。分离出反式- Sgs-4的调节因子，一个单克隆抗体库， 针对唾液腺DNA结合蛋白将被构建 在噬菌体λ中。单克隆抗体将在 用增强子DNA-蛋白质复合物筛选。这些单克隆抗体 将用于筛选cDNA文库。分离的cDNA克隆 用来分离它们的抗体 描述新的基因的调控和表达模式， 基因和蛋白质的DNA结合活性。

The hormone responsive glue genes of Drosophila are expressed at high levels in the salivary glands of late third instar larvae. Unlike the other glue genes, Sgs-4 is expressed at early times in development and in a second tissue, the proventriculus. Dr. Beckendorf proposes to use footprinting, in vitro mutatgenesis, and germ line transformation to establish which cis acting sequences govern this unique expression pattern. Because the Sgs- 4 enhancer is made up of multiple, partially interchangeable elements, the interactions of these elements and the differences in their regulatory functions will be examined. To isolate trans- regulators of Sgs-4, a monoclonal antibody library directed against salivary gland DNA binding proteins will be constructed in phage lambda. Monoclonal antibodies will be isolated after screening with enhancer DNa-protein complexes. These monoclonals will then be used to screen a cDNA library. Isolated cDNA clones and the antibodies used to isolate them will then be used to characterize the regulation and expression patterns of the new genes and the DNA-binding activities of the proteins.